Theileria Parva: Comparative Infectivity of a Ground Tick Stabilate and a Classical 10-Tick Challenge

Abstract

Two groups of cattle, one ECF-sus-ceptible and the other ECF-recovered, were given East Coast fever challenges. The challenge was given either as a classical 10-tick challenge or by inoculation of a stabilate derived from the same batch of ticks. All susceptible animals died from both methods of challenge, with consistently uniform reactions in each case. Animals recovered from ECF consistently withstood challenge. Two reasons are given for preferring a stabilate challenge to a classical 10-tick challenge, namely reproducibility of uniformly lethal challenge over an extended period and the need for less strict confinement of the challenged animals.